Project Summary Compounds from the pharmaceutical and other industries undergo safety and efficacy testing but the in vitro and animal models that are used often fail in their translation to human physiology, resulting in late stage failures during development and significant costs. There is a need to identify more physiologically relevant in vitro systems for both healthy and disease states that translates into the clinic. This need is especially pronounced for pharmaceutical and therapeutic compounds where the dearth of human safety data, particularly for preclinical evaluation of compounds, is largely attributable to inadequate in vitro systems that cannot accurately predict the effects of compound or drug exposures on relevant cells, tissues, and organs. There is a clear need for more life-like systems which incorporate 3D cellular architecture, fluid movement, and mimic in vivo compound dosing with non-linear compound and metabolite gradients that allow repeat low concentration dosing over time courses and amenable to running cell based assays. The scope of this SBIR project is to develop a first-in-class fluidics bio-tool that can promote highly functional 3D liver organoid formation, link multiple-organs and incorporate non-linear compound and metabolite gradients. The 3D organoid SciFlow system to be developed in this work will provide three major advances over current toxicological testing options: 1) Increased physiological relevance through promotion of 3D cellular architecture, and multi-organ systems, 2) Incorporation of non-linear exposure gradient of compounds and metabolites across multi-organ systems, and 3) a simple to use system with SBS-format and broad compatibility with standard laboratory equipment including high content imagers and plate readers. In Phase I, we will complete the following Specific Aims: Aim 1: Characterize and select a non-binding surface chemistry to promote non-adherent cell culture and 3D spheroid formation. Aim 2: Establish a multi-organ system with 3D liver cell cultures capable of increased bioactivation (metabolism) of therapeutic compounds resulting in an increased drug potency on downstream tumor cells. Upon completion of the Phase I aims, our Phase II work will focus on validating the system and scaling the unit for production. Successful completion of this project will result in development of the SciSlick multi-organ 3D system, which will leverage the inter-compartment flow with the ability to culture different cell types, suitable for repeated dosing in long-term to investigate parent compound:metabolite complexities all in an easy to use, accessible microfluidics device.